Continuous emission in the spectra of planetary nebulae

[11] PLASKETT HH, 1936, MN, V96, P402

[12] STOY RH, 1939, PUB ASP, V51, P235

[13] WILLIAMS PC, 1939, PUB MICHIGAN OBS, V7, P147

[14] WILLIAMS RC, 1939, PUB MICHIGAN OBS, V7, P93

[15] Wright W.H., 1918, PUBL LICK OBS, V13, P193

[16] ZANSTRA H, 1936, OBSERVATORY, V59, P314

[17] 1941, AP J, V93, P236

[18] 1938, AP J, V88, P52

[19] 1940, ANN AP, V2

[20] 1936, OBSERVATORY

[11] PLASKETT HH, 1936, MN, V96, P402

[12] STOY RH, 1939, PUB ASP, V51, P235

[13] WILLIAMS PC, 1939, PUB MICHIGAN OBS, V7, P147

[14] WILLIAMS RC, 1939, PUB MICHIGAN OBS, V7, P93

[15] Wright W.H., 1918, PUBL LICK OBS, V13, P193

[16] ZANSTRA H, 1936, OBSERVATORY, V59, P314

[17] 1941, AP J, V93, P236

[18] 1938, AP J, V88, P52

[19] 1940, ANN AP, V2

[20] 1936, OBSERVATORY